1. Technical Field
The present disclosure generally relates to operation of multi-core processors within an information handling system and in particular to reducing execution jitter in multi-core processors within an information handling system.
2. Description of the Related Art
As the value and use of information continue to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes, thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
The information handling system can be designed with one or more multi-core processors. A multi-core processor is a single computing component with two or more independent central processing units, processor cores, or cores that are able to read and execute program instructions or software code. The program instructions or software code can be regular computer instructions. The multiple cores can run multiple instructions at the same time, increasing the overall processing speed for programs. The multiple cores typically are integrated onto a single integrated circuit die or integrated circuit or onto multiple dies in a single chip package.
As processors with multiple cores implement higher and dynamic frequency ranges, these changes can result in non-deterministic code execution timing. Some software applications require very specific or deterministic code execution timing. Examples of these applications include real time applications, financial trading applications, and control applications. It is desirable for these applications to have predictable execution times. Execution jitter is defined as the difference in execution time for a given program or thread between the predicted execution time and the actual execution time at a given frequency. For example, if a given thread is predicted to execute in 10 milliseconds and some measured execution times are 8, 9, 11 and 13 milliseconds, the execution jitter is the difference between the measured times and 10 milliseconds. Execution jitter can occur for threads that execute in either longer or shorter times than the predicted or desired execution times. In order to control the level of execution jitter within an acceptable range, the multiple cores are forced to operate at the lowest operating frequency or lowest performance level. A method for reducing execution jitter in software programs running on multi-core processors is therefore needed.